Strain-induced electronic and optical properties of two-dimensional SnSe/SnS van der Waals heterostructure
Two-dimensional materials have excellent properties,which makes them valuable in the field of material physics.In this paper,the electronic and optical properties of SnSe and SnS monolayers and SnSe/SnS van der Waals heterojunctions are calculated based on the first principles method.Monolayer SnSe and SnS are indirect bandgap semiconductors with a band gap of 0.95 eV and 1.46 eV,while SnSe/SnS are indi-rect bandgap semiconductors with a band gap of 0.47 eV,which is significantly lower than that of their monolayer materials.SnSe/SnS heterojunction has better optical properties than its monolayer material.The virtual part of dielectric function and optical absorption coefficient of SnSe/SnS heterojunction are much lar-ger than that of its monolayer material.The electronic and optical properties of SnSe/SnS heterojunctions under different strains are also studied.Uniaxial strain and biaxial strain can effectively regulate the photoe-lectric properties of SnSe/SnS.The results show that biaxial strain is more effective than a-axis strain and b-axis strain.The energy bands of SnSe/SnS heterojunctions change from indirect to direct band gaps under biaxial strain.The optical absorption coefficient of SnSe/SnS heterojunction can be enhanced by strain regu-lation.This study provides ideas for obtaining materials with better electronic and optical properties.The re-sults show that the SnSe/SnS van der Waals heterojunction has potential application value in the field of op-toelectronic devices.
First principlesSnSe/SnS heterojunctionstrainelectronic properties